If you jam cell phone signals you would be breaking the law. It is against the Federal Communications Commision laws to jam phone or radio signals.

Lets think for a minute that if you jammed the frequencies a cell phone and someone attempted to call-in a emergency where you blocking the signal caused a death. You could be found guilty of negligent homicide. Or something simular you would also have to live with that death, maybe it would be the death of a two year old kid.

You can get them online but there is only one catch you have to be in the police or FBI to be able to buy.Or have a legitimate use for it like be a hospital director or something like that.They use them in some schools and colleges so students don’t cheat but again you have to be in law enforcement to get one.